<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<!--action后边的路径要改为相对路径，不加 / -->
    <form action="login" method="post">
        <input type="text" name="username"><br>
        <input type="password" name="password"><br>
        <input type="submit" value="登录">
    </form>

</body>
</html>